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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Case Study of Insight Homes who built 36 identical houses, three at a time, with increasing energy-efficiency measures in each generation until they arrived at the most cost-effective mix. Advanced framing and high-efficiency HVAC located in a sealed, insulated crawlspace helped them achieve a HERS scores of 49 to 56 and average utility bills of $93 per year.
The Fuel Cycle Options (FCO) campaign in the U.S. DOE Fuel Cycle Research & Development Program conducted a detailed evaluation and screening of nuclear fuel cycles. The process for this study was described at the 2014 ICAPP meeting. This paper reports on detailed insights and questions from the results of the study. The comprehensive study identified continuous recycle in fast reactors as the most promising option, using either U/Pu or U/TRU recycle, and potentially in combination with thermal reactors, as reported at the ICAPP 2014 meeting. This paper describes the examination of the results in detail that indicated that there was essentially no difference in benefit between U/Pu and U/TRU recycle, prompting questions about the desirability of pursuing the more complex U/TRU approach given that the estimated greater challenges for development and deployment. The results will be reported from the current effort that further explores what, if any, benefits of TRU recycle (minor actinides in addition to plutonium recycle) may be in order to inform decisions on future R&D directions. The study also identified continuous recycle using thorium-based fuel cycles as potentially promising, in either fast or thermal systems, but with lesser benefit. Detailed examination of these results indicated that the lesser benefit was confined to only a few of the evaluation metrics, identifying the conditions under which thorium-based fuel cycles would be promising to pursue. For the most promising fuel cycles, the FCO is also conducting analyses on the potential transition to such fuel cycles to identify the issues, challenges, and the timing for critical decisions that would need to be made to avoid unnecessary delay in deployment, including investigation of issues such as the effects of a temporary lack of plutonium fuel resources or supporting infrastructure. These studies are placed in the context of an overall analysis approach designed to provide comprehensive information to the decision-making process.
Increased interest in the use of alternative transportation fuels, such as natural gas, hydrogen, and electricity, is being driven by heightened concern about the climate impacts of gasoline and diesel emissions and our dependence on finite oil resources. A key barrier to widespread adoption of low- and zero-emission passenger vehicles is the availability of refueling infrastructure. Recalling the 'chicken and egg' conundrum, limited adoption of alternative fuel vehicles increases the perceived risk of investments in refueling infrastructure, while lack of refueling infrastructure inhibits vehicle adoption. In this paper, we present the results of a study of the perceived risks and barriers to investment in alternative fuels infrastructure, based on interviews with industry experts and stakeholders. We cover barriers to infrastructure development for three alternative fuels for passenger vehicles: compressed natural gas, hydrogen, and electricity. As an early-mover in zero emission passenger vehicles, California provides the early market experience necessary to map the alternative fuel infrastructure business space. Results and insights identified in this study can be used to inform investment decisions, formulate incentive programs, and guide deployment plans for alternative fueling infrastructure in the U.S. and elsewhere.
The U.S. Department of Energy's Clean Energy Manufacturing Analysis Center (CEMAC) provides objective analysis and up-to-date data on global supply chains and manufacturing of clean energy technologies. Policymakers and industry leaders seek CEMAC insights to inform choices to promote economic growth and the transition to a clean energy economy.
This brief is a compilation of data points and market insights that reflect the state of the project finance market for solar photovoltaic (PV) assets in the United States as of the third quarter of 2017. This information can generally be used as a simplified benchmark of the costs associated with securing financing for solar PV as well as the cost of the financing itself (i.e., the cost of capital). This work represents the second DOE sponsored effort to benchmark financing costs across the residential, commercial, and utility-scale PV markets, as part of its larger effort to benchmark the components of PV system costs.
Point contact tunneling (PCT) spectroscopy measurements are reported over wide areas of cm-sized cut outs from niobium superconducting RF cavities. A comparison is made between a high-quality, conventionally processed (CP) cavity with a high field Q drop for acceleration field E $>$ 20 MV/m and a nitrogen doped (N-doped) cavity that exhibits an increasing Q up to fields approaching 15 MV/m. The CP cavity displays hot spot regions at high RF fields where Q-drop occurs as well as unaffected regions (cold spots). PCT data on cold spots reveals a near ideal BCS density of states (DOS) with gap parameters, $\Delta$ as high as 1.62 meV, that are among the highest values ever reported for Nb. Hot spot regions exhibit a wide distribution of gap values down to $\Delta \sim$ 1.0 meV and DOS broadening characterized by a relatively large value of pair-breaking rate, $\Gamma$, indicating surface regions of significantly reduced superconductivity. In addition, hot spots commonly exhibit Kondo tunneling peaks indicative of surface magnetic moments attributed to a defective oxide. N-doped cavities reveal a more homoegeneous gap distribution centered at $\Delta \sim$ 1.5 meV and relatively small values of $\Gamma/\Delta$. The absence of regions of significantly reduced superconductivity indicates that the N interstitials are playing an important role in preventing the formation of hydride phases and other macroscopic defects which might otherwise severely affect the local, surface superconductivity that lead to hot spot formation. The N-doped cavities also display a significantly improved surface oxide, i.e., increased thickness and tunnel barrier height, compared to CP cavities. These results help explain the improved performance of N-doped cavities and give insights into the origin of the initial increasing Q with RF amplitude.
Over the last two decades, the National Renewable Energy Laboratory (NREL) has been applying its analytical expertise to help guide and advance renewable energy technology research and development (R&D). Working shoulder-to-shoulder with world-class researchers - at NREL, other national laboratories, and universities - and industry partners, NREL analysts continue to search for answers to emerging energy challenges every day. Our objective methodologies and tools are now helping stakeholders assess and prioritize R&D efforts as fast as new innovative technologies transition from concept to commercial application. Throughout that journey, NREL's analyses highlight key technical barriers, compare tradeoffs among proposed technology development pathways, track progress toward performance and cost targets, and illuminate the impacts of proposed innovations. This edition of NREL's Analysis Insights takes a deeper look at the role analysis has played in guiding renewable energy innovation at our laboratory, and beyond. In doing so, the report substantiates what we have known for 20 years - that informed analyses must remain at the leading edge of future R&D efforts.
This presentation provides an overview of the recently-completed annual collection of Federal motor vehicle fleet data in a new more detailed shape, characterizing the Federal fleet of motor vehicles at the individual level. This data was submitted by Federal agencies through the Federal Automotive Statistical Tool (FAST), a Web-based data collection system developed and maintained by INL under a jointly-funded and -managed program for the US Department of Energy and the US General Services Administration. This presentation will cover some of the lessons learned during this first submission of data in this new shape and will explore a few simple examples of new ways this data can be used to gain insights into the makeup and operation of the Federal motor vehicle fleet.
Particulate matter (PM) emissions from internal combustion engines negatively impact public health and global climate. These problems are exacerbated by newer gasoline direct injection engines, which are more fuel-efficient, but also produce more soot than traditional spark ignited engines. Reducing soot formation is therefore of paramount importance in the development of new fuels. A fuel's sooting tendency is a quantitative parameter that describes the sooting behavior of a pure compound or fuel mixture. The yield sooting index (YSI), developed by McEnally and Pfefferle, accurately measures sooting tendencies using small sample quantities. Using an experimental sooting tendency database, we have developed a predictive model for sooting behavior from a quantitative structure-activity relationship (QSAR). It was developed so that input molecules are first decomposed into individual carbon-type fragments for which the sooting tendency contribution can be assigned based on a Bayesian linear regression against the experimental database. The model's predictive accuracy is comparable to its training performance using leave-one-out cross-validation. We have used this model to provide quantitative insights into the effects of chemical structure on soot formation, but excitingly, we have also been able to readily identify the presence of more complicated kinetic sooting mechanisms for structures which are extreme outliers. Oxygenated aromatics can be produced readily from biomass as renewable sources and oxygenated aromatics with very similar structures tend to have a much lower sooting tendency, for example methoxybenzene (anisole, 107), 2-methylphenol (m-cresol, 103), 2-ethylphenol (120), 3-ethylphenol (138) and 1-phenylethanol (142). Thus, the presence of just one oxygen atom in an aromatic compound can drastically alter the reaction pathways leading to soot precursors. We have applied density functional theory (DFT) calculations and flow reactor experiments to examine how oxygenation alters reaction pathways in a combustion environment. This study has allowed us to gain understanding on how the location of an oxygenated functional group influences soot formation. Our work provides a blueprint for the design of oxygenated fuels from biomass, which minimize the production of soot in low oxygen environments.
In this work we leverage the Uber movement dataset for the Los Angeles (LA) area where partial TAZ to TAZ (Traffic Analysis Zone) trip time data is available. We first create a TAZ-TAZ network based on nearest neighbors and propose a model that allows us to complete the $(O-D)$ (Origin-Destination) travel time matrix, using optimization methods such as non-negative least squares. We apply these algorithms for several communities in the TAZ-TAZ network and present insights in the form of completed $(O-D)$ matrices and associated temporal trends. We qualify the error performance and scalability of our flows. We conclude by pointing out the directions in our ongoing work to improve the quality and scale of travel time estimation.
This presentation, part of the International Summit on Breakout Technologies of Engine and Fuel 2018, discusses fuel properties for advanced spark ignition engines and insights from the U.S. DOE Co-Optima Project.
The fundamental understanding of the boiling-associated heat transfer, including sliding bubble effect, is still challenging despite the intensive research for decades in both experimental and computational boiling research communities. One of the main difficulties of boiling experiment come from the fact that direct observation of the underlying principle through experiment is very difficult due to the high complexity of the boiling phenomenon. Also, since the heat transfer characteristics associated with boiling is the result of non-linear interaction of various physical parameters coupled to each other, it is challenging to find the relationship between the parameters for modeling. This paper discusses the authors’ past and ongoing boiling research under CASL (Consortium for Advanced Simulation of Light Water Reactors) program, including the efforts to overcome the difficulties of boiling measurement and model development. In particular, we focus on describing the major achievements, lessons learnt, and ongoing challenges for the CFD boiling closure model development based on the high-fidelity subcooled flow boiling experiment at Texas A&M University (TAMU). The major research achievements discussed through this paper include (i) novel boiling measurement strategy and high-fidelity validation data production, (ii) dedicated effort to identify the critical measurement issues in boiling experiment, (iii) new physical insight into sliding bubble heat transfer mechanisms, and (iv) new boiling closure model development. Discussion is also made on the ongoing challenges for the boiling closure model development and the future research plan based on the lessons learnt.
Conversion of methanol and dimethyl ether to high-octane gasoline catalyzed by beta zeolite (BEA) provides an opportunity for the production of high-quality fuels from renewable carbon sources (e.g., gasified biomass). Recent research demonstrated that a Cu-modified BEA zeolite catalyst (Cu/BEA) offered advantages over the unmodified BEA catalyst due to multifunctional Cu species that enabled incorporation of co-fed H2, reactivation of light alkanes, and reduction of products from the aromatic hydrocarbon pool. The shift in hydrocarbon pool chemistry has the potential to influence the identity and relative composition of surface carbon species that are often linked to deactivation. A detailed understanding of these carbon species is important to develop an effective and efficient regeneration procedure that can enable the transition from fundamental catalyst development to commercial application. Here, we applied complementary ex situ and in situ characterization techniques to compare the structures of surface carbon species on post-reaction Cu/BEA and unmodified BEA catalysts. Both catalysts contained acyclic and aromatic hydrocarbons along with graphitic carbon species. However, the post-reaction Cu/BEA catalyst had a lower polycyclic aromatic content, and further, the graphitic species were more hydrogenated and defective. It was also found that the presence of Cu promoted carbon removal at lower temperatures than for unmodified BEA through activation of O2 by Cu during thermal oxidation. The fundamental insight into the composition of surface carbon species enabled the design of an effective and efficient regeneration strategy for the DME homologation reaction over Cu/BEA, resulting in full recovery of the catalyst activity.
This paper summarizes the major insights gained from aerosol retention capability of a tube bundle that simulates the break stage of the secondary side of a failed steam generator under dry SGTR conditions. This scenario is highly relevant in nuclear safety since it affects the potential retention of radioactive particles in case of meltdown sequences with a SGTR. An 8-test experimental campaign has been carried out, extending the current database on the decontamination capability of the steam generator. The effects of the breach features (shape and size) and the particle nature (SiO{sub 2} and TiO{sub 2}) on the collection efficiency have been explored. The results confirmed the strong effect of the physical nature even when tube breaks in a fish-mouth mode. Loose aggregates (i.e. TiO{sub 2}) would be trapped to a limited extent (less than 25%); while single- or few-aggregates (i.e. SiO{sub 2}) would undergo a quite effective removal (i.e. over 75%). For fish-mouth breaches and SiO{sub 2} particles, the breach size has been found to moderately affect retention efficiency. Furthermore, the breach shape does not seem to have any effect on the net collection efficiency within the break stage, no matter the particle type. However, individual tube measurements indicate notably different deposition patterns, although an effect of the facility geometry cannot be disregarded as a key player in this observation. (authors)
For decades, the United States and other nations with nuclear programs have been planning for permanent disposition of spent nuclear fuel and high-level waste, to address the increasingly difficult problem of storing these materials for the long term. These plans are complicated by issues ranging from technological factors to regulatory approaches and public concerns about health and environmental protection. In its 2012 report, the Blue Ribbon Commission (BRC) on America's Nuclear Future identified a number of recommendations for creating a safe, long-term solution to the nation's problem of managing and disposing of its spent fuel and high-level radioactive waste. These include a recommendation that the U.S. Environmental Protection Agency (EPA) revise its standards for a high-level waste repository. The EPA is currently reviewing and synthesizing literature relevant to such standards, including: (1) existing national and international standards and guidelines for repositories; and (2) benefits and barriers to such standards, including limitations related to current technologies, as well as siting, licensing, and construction processes. This paper highlights findings of this literature review and synthesis. More than 90 countries, from Albania to Vietnam and Yemen, were identified as potential sources of relevant information based on existing nuclear programs or consideration of such programs to address future energy needs. Pursuant to the BRC recommendations, the U.S. Department of Energy (DOE) has compiled extensive information resources relevant to spent fuel and radioactive waste repositories in the Centralized Used Fuel Resource and Information Exchange (CURIE) database developed by Oak Ridge National Laboratory. Further valuable sources of information include annual proceedings of recent Waste Management Symposia, which provide insights into recent trends and progress across various national and international programs. Recent literature from a number of countries, including the United States and Canada, and the United Kingdom, Finland, Sweden, France, Germany, and other countries in Western Europe, as well as other regions including Australia, indicates that consent-based siting has emerged as a dominant theme. In addition to effective siting processes, key program needs identified in the literature include regulatory standards and performance context, as well as reliable technologies and engineered systems, such as for deep drilling and assured safe containment of these radioactive materials extending into the very long term. (authors)
The technical ability to decommission NPPs shut down after normal operation has been well demonstrated. However, concerns remain about the ability to accurately calculate and demonstrate the validity of decommissioning cost estimates, and to control costs during decommissioning. This paper describes recent international guidance on quality cost estimates for nuclear decommissioning projects and explores the potential added value that could be attained through more systematic analysis and reporting of decommissioning project costs. The OECD Nuclear Energy Agency (NEA) and the International Atomic Energy Agency (IAEA) have long been concerned about the need to promote greater transparency in decommissioning costing and have collaborated in a number of initiatives in pursuit of this objective. Together with the European Commission, they published 'The International Structure for Decommissioning Costing (ISDC)' in 2012. The ISDC provides a useful common reporting format for decommissioning costing. The NEA has also published guidance on the international peer reviews of decommissioning cost studies (2014) and on the practice of decommissioning cost estimation (2015). In September 2017, the NEA and IAEA published detailed guidance on addressing uncertainties in decommissioning cost estimates (the 'Addressing Uncertainties' report). This joint report sets out an approach to treating uncertainties reflecting current good practices in cost estimating. Specifically, it describes how uncertainties in decommissioning cost estimation can be addressed using standardized methods of estimating uncertainty and risk analysis. Its recommendations aim at enabling a consistent and comprehensive treatment of risk and uncertainty in the preparation of decommissioning cost estimates. Together these publications establish a good basis for producing comprehensive and high-quality cost estimates for nuclear decommissioning projects and for enhancing confidence in the estimates through improving transparency concerning the underpinning data and calculations, and more explicit representation of the uncertainties that may impact on project costs. There is increasing attention on understanding variations between cost estimates and apparent escalation of decommissioning costs. This arises both from the need to assure the adequacy of financing arrangements for future decommissioning projects and the ambition to improve the performance and ensure value-for-money in the delivery of decommissioning projects and services. A systematic analysis of actual decommissioning project costs in relation to the cost estimates would be expected to yield valuable insights about key cost drivers in actual decommissioning projects, and the extent to which current cost estimates accurately capture and reflect these. Aligning the reporting of decommissioning project costs with the underpinning cost estimates for the projects would also facilitate the identification of causes of major deviations between projected and actual costs. (authors)
It was very hard to estimate how the accident had progressed at each unit of Fukushima Daiichi NPS at the early stage of post-accident analytical activities, because the knowledge relevant to BWR severe accident phenomena and progression was insufficient and the collected data was very limited since complete station blackout (loss of AC and DC power) was occurred at Fukushima Daiichi NPS. However, because of the progression of the measured data analysis, system behavior or response of reactors before the core melt has already been clarified. System behaviors after the core melt have been clarified, as well. Measured data and circumstantial evidence clearly indicated that the fuel temperature went up to melting point and the RPV was damaged by the molten core, and the Fukushima accident is known as a more serious accident than TMI-2 because of including ex-vessel phenomena. But, the information regarding detailed accident progression (for example, amount of melted fuel and timing of RPV breach, etc.) is still unclear and we are struggling to solve such a detailed accident progression. At present, there are two challenges in front of us. One of them is to improve nuclear reactor safety by applying the insights from the Fukushima accident and the other is to solve unclear issues before conducting the first RPV internal investigation. Tokyo Electric Power Company is willing to stand up against these two challenges as the company concerned and appreciate supports of the world nuclear community. (authors)
There are unique challenges and opportunities at the nexus of agriculture and energy. This presentation will feature a social science overview of agrivoltaics, which is the practice of combining solar energy and agricultural production on the same land. Centering on recent research and commercial insights, this presentation will discuss the implications of lessons learned in the Northeast and highlight key considerations for future agrivoltaic R&D in Pennsylvania.